Many forms of immersion lances are known and used for the mixing, degassing or desulphurization of steel melts. The lances must be designed in such a manner that they withstand the considerable stressings which occur during the blowing operation due to the actual temperature and the change in temperature, erosional attack by the metal and the slag, chemical processes and mechanical stressing due to the static and dynamic mechanical forces in the form of buoyancy and vibrations.
It is an object of the invention to provide an immersion lance whose heat-dissipating surface is increased to a substantial extent, so that the thermal stressing of the refractory material is substantially lower, the result being an extended service life. Further objects of the invention are to substantially enhance the moment of resistence of the whole lance and to obviate the effect of destructive oscillations on the lance.